"The Earth is a sphere (or more correctly a spheroid), and a globe is the best representation or model of the Earth's surface. A map, on the other hand, must represent as accurately as possible the 3-dimensional Earth on a 2-dimensional (flat) surface. In producing a map it is important to ensure a known relationship between true locations on the Earth and the corresponding points on the map. Therefore, the construction of any map must begin with a map projection ..."
From The Atlas of Canada website - https://www.nrcan.gc.ca/earth-sciences/geography/atlas-canada

Another good introduction to projection is here: http://en.wikipedia.org/wiki/Map_projection

What is the GNWT Standard projection?

The NWT Centre for Geomatics uses the NWT Lambert Conformal Conic projection. Conceptually, the projection seats a cone over the sphere of the Earth and projects the surface conformally conformally onto the cone. The cone is unrolled, and the parallel that was touching the sphere is assigned a unit scale. That parallel is called the standard parallel. By scaling the resulting map, two parallels can be assigned a unit scale, with scale decreasing between the two parallels and increasing outside them. This gives the projection two standard parallels. The central meridian is a straight line about which the projection is symmetrical. In this case, it's the 112th meridian.

Name: NAD83 / NWT Lambert
EPSG Code: CRS 3580
Projection: Lambert Conformal Conic
Datum: NAD83
1st standard parallel: 62.0
2nd standard parallel: 70.0
Central meridian: -112.0
Latitude of origin: 0.0
False easting: 0
False northing: 0
Scale Factor 1

Another type of projection that is suitable for larger scale maps of the NWT is the UTM projection. UTM projections are broken down into 6 degree zones. Zones 8 through thirteen cover the breadth of the NWT. Each of these UTM zones forms the basis of a separate map projection. Because the zones are relatively narrow, the distortion is small and may be ignored by most map users, making it very suitable for community and localized mapping projects.

Why I cannot see the WMS service in Preview?

The WMS service is based on ISO theme categories, meaning that all vector data related to that theme will be stored within that WMS service. For example, the Ecological/Biological theme will contain species at risk data, wildlife habitat zones, and fire history. Most of the layers have been turned off by default because it is too cartographically complex to represent them all at the same time. To preview the WMS service, either use our Spatial Data Warehouse Viewer or utilize your own GIS software such as Google Earth.

Where do I reference or view WMS service Metadata?

This is how we organize our data; A link to our WMS services can be found within our map viewer within the advance tool bar. You will have to click on the layers within this ISO theme to find the specific descriptions for the individual layer data sources. To learn how to reference a WMS go to http://www.opengeospatial.org/. Many different methods of citation formats are availible.

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Data FAQ

Where can I get NTS map sheets?

Where can I find other GNWT maps or data?

Where can I make my own map?

What digital data Is available or downloadable?

Why is projection important?

What is the GNWT Standard projection?

Why I cannot see the WMS service in Preview?

Where do I reference or view WMS service Metadata?